1. Field of the Invention
The present invention relates to a temperature control device that controls the temperature of a heated object with a heat transfer member for transferring heat from a heat source, and to an image forming apparatus including the temperature control device.
2. Description of the Related Art
There is an increasing demand for energy saving. In image forming apparatuses, including a heating-type fixing device such as a copying machine and a printer, it is most effective to utilize waste heat from the fixing device. Various techniques of utilizing waste heat from the fixing device have been proposed.
As one technique, Japanese Patent Laid-Open No. 2004-061580 discloses that waste heat from a fixing device is transferred by a heat pipe having excellent heat transfer performance so as to warm sheets stored in a sheet feeding device.
Unfortunately, the above-described technique has some disadvantages. In consideration of turn-off of the fixing device, a heater for warming sheets in the sheet feeding device is provided. In this case, the fixing device is driven and heated, and heat is transferred from the fixing device to the sheet feeding device. However, when heating of the fixing device is stopped, the temperature of the fixing device gradually falls, and sometimes falls below the temperature in the sheet feeding device. In this case, heat is transferred from a higher-temperature portion to a lower-temperature portion in the structure using the heat pipe, that is, heat is transferred from the sheet feeding device to the fixing device. For this reason, the heater for maintaining a fixed temperature of the sheet feeding device heats not only the sheet feeding device, but also the fixing device. Consequently, power consumed by the heater increases as the temperature of the fixing device decreases.